chore: developer experience - pre-commit hook, ai instructions, yaml formatting (#374)

* chore: developer experience - pre-commit hook, ai instructions, yaml formatting for prettier

* no prettierrc, editorconfig instead

* fixes from copilot suggestions

---------

Co-authored-by: Ferdinand Schober <ferdinandschober20@gmail.com>

.githooks/pre-commit

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Ensure we're at the repo root
+cd "$(git rev-parse --show-toplevel)" || exit 1
+
+echo "Running cargo fmt (auto-format)..."
+# Run formatter to apply fixes but do not stage them. If formatting changed,
+# fail the commit so the user can review and stage the changes manually.
+cargo fmt --all
+if ! git diff --quiet --exit-code; then
+  echo "" >&2
+  echo "ERROR: cargo fmt modified files. Review changes, stage them, and commit again." >&2
+  git --no-pager diff --name-only
+  exit 1
+fi
+
+echo "Running cargo clippy..."
+# Matches CI: deny warnings to keep code health strict
+if ! cargo clippy --workspace --all-targets --all-features -- -D warnings; then
+  echo "" >&2
+  echo "ERROR: clippy found warnings/errors. Fix them before committing." >&2
+  exit 1
+fi
+
+echo "Running cargo test..."
+if ! cargo test --workspace --all-features; then
+  echo "" >&2
+  echo "ERROR: Some tests failed. Fix tests before committing." >&2
+  exit 1
+fi
+
+echo "All pre-commit checks passed."
+exit 0